Excess adipose tissue and sarcopenia promotes a unique multifaceted challenge that may exacerbate the risk of morbidity and mortality in the obese, elderly population. We have demonstrated the effectiveness of essential amino acids in stimulating muscle protein synthesis under a variety of physiological scenarios, even under conditions of additional metabolic stress. Due to limited application of these strategies in our studies, we have developed a product uniquely suited to address muscle wasting during weight loss, and based our development on the criteria of taste, volume, price and packaging. Based on the unique formulation of ingredients, we have chosen to market the product under the brand name BeneVia(R) Weight Loss. While the development of BeneVia(R) Weight Loss is based upon theoretical and scientific rationale, the actual product has not been tested in a clinical scenario. Thus, the goal of this Phase 1 application will be to determine if the of BeneVia(R) Weight Loss stimulates muscle protein synthesis and maintains muscle mass more effectively than currently available products for obese, elderly individuals. If the results of the Phase 1 test are positive, the Phase 2 study will be a double-blind placebo outcome trial comparing BeneVia(R) Weight Loss with a popular nutritional supplement. In this way, we can determine the efficacy of the products towards optimal reduction of adipose tissue and the adequate maintenance of muscle mass. We will also utilize stable isotope methodology to quantify muscle protein synthesis and relate acute supplement-induced changes in metabolism to long-term outcome based parameters. PUBLIC HEALTH RELEVANCE: This proposal describes a nutritional supplement designed to maintain muscle mass, even under the metabolic challenge of caloric restriction-induced weight loss in obese, elderly individuals. If successful, the result is an economical nutritional product that can be utilized to attenuate morbidity and mortality with aging. This will not only improve quality of life in elderly, but have a significant impact on overall health care costs.